Category Archives: Fotodiox Pronto


My M42 Lenses on the Fotodiox Pronto Autofocus Adapter

In this article its all about the compability of my M42 lenses to the Fotodiox Pronto (Techart PRO AF) adapter.

As the autofocus works with all lenses, better when its brigt worse when its darker, this article is about if the 4,5mm focusway is enough. (More Info about the adapter)

The test was done with this setup:

Sony Alpha 7RII + Fotodiox Pronto + Fotodiox M42 auf Leica M + M42 Lens


Needs manual prefocus?
prefocus steps
additional info

Carl Zeiss Flektogon
20mm f2,8



Helios 44-2
58mm f2
yes 2 Only works with the center AF spot
Carl Zeiss Flektogon
35mm f2,8
yes 3 Only works with the center AF spot
Zenitar Fisheye
16mm f2,8
no 0 none
Meyer Optik Görlitz
58mm f1,9
yes 2 none
55mm f1,4
yes 2 none
Meyer Optik Görlitz
100mm f2,8
yes 4 none

Fotodiox Pronto – Autofocus with old lenses

Fotodiox Pronto

As I came home from the office today [22.12.2017] there was a parcel waiting for me. Mr. Schmitz from the german Lumiere-Shop borrowed me one of his Fotodiox Pronto adapters untill February 2018. By then I will do several testing with this adapter to check out how it performs and which lenses it works good with.

Next to the Pronto adapter iitself there was an additional Fotodiox M42 to Leica M Adapter in the parcel. This adapter allows me to use my M42 lenses with autofocus.

First impression

I can’t tell anything about the box as my adapter was already unboxed and came in a plastic bag.

The housing of the adapter is made from metal. No plastic. The inner moving part is brass-coloured and looks really cool. I really have to say that the adapter feel really well finished . No wiggling, no sharp edges and no strange uneven joints.

The adapter sticks out at the bottom of the camera, when there is no L-Bracket mounted to the camera. If you want to place the camera on the ground it will not be balanced well and fall over. If you use an L-Bracket the adapter and the bracket are on the same plain. It stands rock solid.


The Fotodiox adapter works the same way as you would when focusing a avintage lens. It shifts the lens forth and back to get the subject in focus. The maximum shifted distance is 4,5mm.

The adapter uses the sony Phase-Detection-Points to see if there is something in focus or not. Cameras which only have Contrast-AF-Points,like the A6000, will not be able to use this system.

Following posts

In the next post i will test all my M42 lenses. I’ll test if the focus works, if the 4,5mm are enough or if you have to pre-focus yourself and i will try to test the speed of focus with different apertures.

If you have any questions about the adapter feel free to leave them in a comment.